Weighing scale



FIG. 1 is a top, front and left side perspective view of a weighing scale showing my new design;

FIG. 2 is a top plan view;

FIG. 3 is a front elevational view;

FIG. 4 is a rear elevational view;

FIG. 5 is a right side elevational view; and,

FIG. 6 is a bottom plan view thereof.

The broken line showing of numbers on the display screen is environmental only and forms no part of the claimed design. 

The ornamental design for a weighing scale, as shown and described. 